<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style type="text/css">
        /* 1.选择器的分组 */
        h1,.box,p{
            color: aqua;
        }
        p{
            width: 100px;
            background-color: #9999;
            color: blue;
        }

        /*2.样式继承*/
        .test{
            font-size: 28px;
            color: aqua;
        }
        .test span{
            font-weight: bold;/*加粗*/
            font-size: 18px;/*改写父元素传过来的样式*/
        }
    </style>
</head>
<body>
    <h1>h1</h1>
    <div class="box">box</div>
    <p>p</p>

    <div class="test">这是一段测试<span>内容</span></div>
</body>
</html>